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<th width="100%" align="center">The gdk-pixbuf Library</th>
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                <a href="#gdk-pixbuf-scaling.description" class="shortcut">Description</a>
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<div class="refentry" lang="en">
<a name="gdk-pixbuf-scaling"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="gdk-pixbuf-scaling.top_of_page"></a>Scaling</span></h2>
<p>Scaling — Scaling pixbufs and scaling and compositing pixbufs</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv">
<a name="gdk-pixbuf-scaling.synopsis"></a><h2>Synopsis</h2>
<pre class="synopsis">

#include &lt;gdk-pixbuf/gdk-pixbuf.h&gt;

enum                <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a>;
<a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *         <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-scale-simple" title="gdk_pixbuf_scale_simple ()">gdk_pixbuf_scale_simple</a>             (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         int dest_width,
                                                         int dest_height,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type);
void                <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-scale" title="gdk_pixbuf_scale ()">gdk_pixbuf_scale</a>                    (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *dest,
                                                         int dest_x,
                                                         int dest_y,
                                                         int dest_width,
                                                         int dest_height,
                                                         double offset_x,
                                                         double offset_y,
                                                         double scale_x,
                                                         double scale_y,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type);
<a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *         <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-composite-color-simple" title="gdk_pixbuf_composite_color_simple ()">gdk_pixbuf_composite_color_simple</a>   (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         int dest_width,
                                                         int dest_height,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type,
                                                         int overall_alpha,
                                                         int check_size,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint32"
>guint32</a> color1,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint32"
>guint32</a> color2);
void                <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-composite" title="gdk_pixbuf_composite ()">gdk_pixbuf_composite</a>                (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *dest,
                                                         int dest_x,
                                                         int dest_y,
                                                         int dest_width,
                                                         int dest_height,
                                                         double offset_x,
                                                         double offset_y,
                                                         double scale_x,
                                                         double scale_y,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type,
                                                         int overall_alpha);
void                <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-composite-color" title="gdk_pixbuf_composite_color ()">gdk_pixbuf_composite_color</a>          (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *dest,
                                                         int dest_x,
                                                         int dest_y,
                                                         int dest_width,
                                                         int dest_height,
                                                         double offset_x,
                                                         double offset_y,
                                                         double scale_x,
                                                         double scale_y,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type,
                                                         int overall_alpha,
                                                         int check_x,
                                                         int check_y,
                                                         int check_size,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint32"
>guint32</a> color1,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint32"
>guint32</a> color2);
enum                <a class="link" href="gdk-pixbuf-scaling.html#GdkPixbufRotation" title="enum GdkPixbufRotation">GdkPixbufRotation</a>;
<a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *         <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-rotate-simple" title="gdk_pixbuf_rotate_simple ()">gdk_pixbuf_rotate_simple</a>            (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkPixbufRotation" title="enum GdkPixbufRotation">GdkPixbufRotation</a> angle);
<a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *         <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-flip" title="gdk_pixbuf_flip ()">gdk_pixbuf_flip</a>                     (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"
>gboolean</a> horizontal);
</pre>
</div>
<div class="refsect1" lang="en">
<a name="gdk-pixbuf-scaling.description"></a><h2>Description</h2>
<p>
    The <span class="application">gdk-pixbuf</span> contains functions to scale pixbufs, to scale
    pixbufs and composite against an existing image, and to scale
    pixbufs and composite against a solid color or checkerboard.
    Compositing a checkerboard is a common way to show an image with
    an alpha channel in image-viewing and editing software.
  </p>
<p>
    Since the full-featured functions (<a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-scale" title="gdk_pixbuf_scale ()"><code class="function">gdk_pixbuf_scale()</code></a>,
    <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-composite" title="gdk_pixbuf_composite ()"><code class="function">gdk_pixbuf_composite()</code></a>, and <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-composite-color" title="gdk_pixbuf_composite_color ()"><code class="function">gdk_pixbuf_composite_color()</code></a>) are
    rather complex to use and have many arguments, two simple
    convenience functions are provided, <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-scale-simple" title="gdk_pixbuf_scale_simple ()"><code class="function">gdk_pixbuf_scale_simple()</code></a> and
    <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-composite-color-simple" title="gdk_pixbuf_composite_color_simple ()"><code class="function">gdk_pixbuf_composite_color_simple()</code></a> which create a new pixbuf of a
    given size, scale an original image to fit, and then return the
    new pixbuf.
  </p>
<p>
   Scaling and compositing functions take advantage of MMX hardware
   acceleration on systems where MMX is supported.  If gdk-pixbuf is built
   with the Sun mediaLib library, these functions are instead accelerated
   using mediaLib, which provides hardware acceleration on Intel, AMD,
   and Sparc chipsets.  If desired, mediaLib support can be turned off by
   setting the GDK_DISABLE_MEDIALIB environment variable.
  </p>
<p>
    The following example demonstrates handling an expose event by
    rendering the appropriate area of a source image (which is scaled
    to fit the widget) onto the widget's window.  The source image is
    rendered against a checkerboard, which provides a visual
    representation of the alpha channel if the image has one. If the
    image doesn't have an alpha channel, calling
    <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-composite-color" title="gdk_pixbuf_composite_color ()"><code class="function">gdk_pixbuf_composite_color()</code></a> function has exactly the same effect
    as calling <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-scale" title="gdk_pixbuf_scale ()"><code class="function">gdk_pixbuf_scale()</code></a>.
  </p>
<div class="example">
<a name="id2895348"></a><p class="title"><b>Example 2. Handling an expose event.</b></p>
<div class="example-contents"><pre class="programlisting">
gboolean
expose_cb (GtkWidget *widget, GdkEventExpose *event, gpointer data)
{
  GdkPixbuf *dest;
  dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, event-&gt;area.width, event-&gt;area.height);
  gdk_pixbuf_composite_color (pixbuf, dest,
                              0, 0, event-&gt;area.width, event-&gt;area.height,
                              -event-&gt;area.x, -event-&gt;area.y,
                              (double) widget-&gt;allocation.width / gdk_pixbuf_get_width (pixbuf),
                              (double) widget-&gt;allocation.height / gdk_pixbuf_get_height (pixbuf),
                              GDK_INTERP_BILINEAR, 255,
                              event-&gt;area.x, event-&gt;area.y, 16, 0xaaaaaa, 0x555555);
  gdk_draw_pixbuf (widget-&gt;window, widget-&gt;style-&gt;fg_gc[GTK_STATE_NORMAL], dest,
                   0, 0, event-&gt;area.x, event-&gt;area.y,
                   event-&gt;area.width, event-&gt;area.height,
                   GDK_RGB_DITHER_NORMAL, event-&gt;area.x, event-&gt;area.y);
  gdk_pixbuf_unref (dest);
  return TRUE;
}
  </pre></div>
</div>
<br class="example-break">
</div>
<div class="refsect1" lang="en">
<a name="gdk-pixbuf-scaling.details"></a><h2>Details</h2>
<div class="refsect2" lang="en">
<a name="GdkInterpType"></a><h3>enum GdkInterpType</h3>
<pre class="programlisting">typedef enum {
	GDK_INTERP_NEAREST,
	GDK_INTERP_TILES,
	GDK_INTERP_BILINEAR,
	GDK_INTERP_HYPER
} GdkInterpType;
</pre>
<p>
    This enumeration describes the different interpolation modes that
    can be used with the scaling functions. <em class="parameter"><code>GDK_INTERP_NEAREST</code></em> is
    the fastest scaling method, but has horrible quality when
    scaling down. <em class="parameter"><code>GDK_INTERP_BILINEAR</code></em> is the best choice if you
    aren't sure what to choose, it has a good speed/quality balance.
    </p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
<p>
	Cubic filtering is missing from the list; hyperbolic
	interpolation is just as fast and results in higher quality.
      </p>
</div>
<p>
  </p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><a name="GDK-INTERP-NEAREST--CAPS"></a><span class="term"><code class="literal">GDK_INTERP_NEAREST</code></span></p></td>
<td>Nearest neighbor sampling; this is the fastest
and lowest quality mode. Quality is normally unacceptable when scaling
down, but may be OK when scaling up.
</td>
</tr>
<tr>
<td><p><a name="GDK-INTERP-TILES--CAPS"></a><span class="term"><code class="literal">GDK_INTERP_TILES</code></span></p></td>
<td>This is an accurate simulation of the PostScript
image operator without any interpolation enabled.  Each pixel is
rendered as a tiny parallelogram of solid color, the edges of which
are implemented with antialiasing.  It resembles nearest neighbor for
enlargement, and bilinear for reduction.
</td>
</tr>
<tr>
<td><p><a name="GDK-INTERP-BILINEAR--CAPS"></a><span class="term"><code class="literal">GDK_INTERP_BILINEAR</code></span></p></td>
<td>Best quality/speed balance; use this mode by
default. Bilinear interpolation.  For enlargement, it is
equivalent to point-sampling the ideal bilinear-interpolated image.
For reduction, it is equivalent to laying down small tiles and
integrating over the coverage area.
</td>
</tr>
<tr>
<td><p><a name="GDK-INTERP-HYPER--CAPS"></a><span class="term"><code class="literal">GDK_INTERP_HYPER</code></span></p></td>
<td>This is the slowest and highest quality
reconstruction function. It is derived from the hyperbolic filters in
Wolberg's "Digital Image Warping", and is formally defined as the
hyperbolic-filter sampling the ideal hyperbolic-filter interpolated
image (the filter is designed to be idempotent for 1:1 pixel mapping).
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="gdk-pixbuf-scale-simple"></a><h3>gdk_pixbuf_scale_simple ()</h3>
<pre class="programlisting"><a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *         gdk_pixbuf_scale_simple             (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         int dest_width,
                                                         int dest_height,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type);</pre>
<p>
Create a new <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> containing a copy of <em class="parameter"><code>src</code></em> scaled to
<em class="parameter"><code>dest_width</code></em> x <em class="parameter"><code>dest_height</code></em>. Leaves <em class="parameter"><code>src</code></em> unaffected.  <em class="parameter"><code>interp_type</code></em>
should be <a class="link" href="gdk-pixbuf-scaling.html#GDK-INTERP-NEAREST--CAPS"><span class="type">GDK_INTERP_NEAREST</span></a> if you want maximum speed (but when
scaling down <a class="link" href="gdk-pixbuf-scaling.html#GDK-INTERP-NEAREST--CAPS"><span class="type">GDK_INTERP_NEAREST</span></a> is usually unusably ugly).  The
default <em class="parameter"><code>interp_type</code></em> should be <a class="link" href="gdk-pixbuf-scaling.html#GDK-INTERP-BILINEAR--CAPS"><span class="type">GDK_INTERP_BILINEAR</span></a> which offers
reasonable quality and speed.
</p>
<p>
You can scale a sub-portion of <em class="parameter"><code>src</code></em> by creating a sub-pixbuf
pointing into <em class="parameter"><code>src</code></em>; see <a class="link" href="gdk-pixbuf-creating.html#gdk-pixbuf-new-subpixbuf" title="gdk_pixbuf_new_subpixbuf ()"><code class="function">gdk_pixbuf_new_subpixbuf()</code></a>.
</p>
<p>
For more complicated scaling/compositing see <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-scale" title="gdk_pixbuf_scale ()"><code class="function">gdk_pixbuf_scale()</code></a>
and <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-composite" title="gdk_pixbuf_composite ()"><code class="function">gdk_pixbuf_composite()</code></a>.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>src</code></em> :</span></p></td>
<td> a <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_width</code></em> :</span></p></td>
<td> the width of destination image
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_height</code></em> :</span></p></td>
<td> the height of destination image
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>interp_type</code></em> :</span></p></td>
<td> the interpolation type for the transformation.
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> the new <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>, or <a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL--CAPS"
><code class="literal">NULL</code></a> if not enough memory could be
allocated for it.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="gdk-pixbuf-scale"></a><h3>gdk_pixbuf_scale ()</h3>
<pre class="programlisting">void                gdk_pixbuf_scale                    (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *dest,
                                                         int dest_x,
                                                         int dest_y,
                                                         int dest_width,
                                                         int dest_height,
                                                         double offset_x,
                                                         double offset_y,
                                                         double scale_x,
                                                         double scale_y,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type);</pre>
<p>
Creates a transformation of the source image <em class="parameter"><code>src</code></em> by scaling by
<em class="parameter"><code>scale_x</code></em> and <em class="parameter"><code>scale_y</code></em> then translating by <em class="parameter"><code>offset_x</code></em> and <em class="parameter"><code>offset_y</code></em>,
then renders the rectangle (<em class="parameter"><code>dest_x</code></em>, <em class="parameter"><code>dest_y</code></em>, <em class="parameter"><code>dest_width</code></em>,
<em class="parameter"><code>dest_height</code></em>) of the resulting image onto the destination image
replacing the previous contents.
</p>
<p>
Try to use <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-scale-simple" title="gdk_pixbuf_scale_simple ()"><code class="function">gdk_pixbuf_scale_simple()</code></a> first, this function is
the industrial-strength power tool you can fall back to if
<a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-scale-simple" title="gdk_pixbuf_scale_simple ()"><code class="function">gdk_pixbuf_scale_simple()</code></a> isn't powerful enough.
</p>
<p>
If the source rectangle overlaps the destination rectangle on the
same pixbuf, it will be overwritten during the scaling which
results in rendering artifacts.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>src</code></em> :</span></p></td>
<td> a <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest</code></em> :</span></p></td>
<td> the <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> into which to render the results
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_x</code></em> :</span></p></td>
<td> the left coordinate for region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_y</code></em> :</span></p></td>
<td> the top coordinate for region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_width</code></em> :</span></p></td>
<td> the width of the region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_height</code></em> :</span></p></td>
<td> the height of the region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>offset_x</code></em> :</span></p></td>
<td> the offset in the X direction (currently rounded to an integer)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>offset_y</code></em> :</span></p></td>
<td> the offset in the Y direction (currently rounded to an integer)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>scale_x</code></em> :</span></p></td>
<td> the scale factor in the X direction
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>scale_y</code></em> :</span></p></td>
<td> the scale factor in the Y direction
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>interp_type</code></em> :</span></p></td>
<td> the interpolation type for the transformation.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="gdk-pixbuf-composite-color-simple"></a><h3>gdk_pixbuf_composite_color_simple ()</h3>
<pre class="programlisting"><a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *         gdk_pixbuf_composite_color_simple   (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         int dest_width,
                                                         int dest_height,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type,
                                                         int overall_alpha,
                                                         int check_size,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint32"
>guint32</a> color1,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint32"
>guint32</a> color2);</pre>
<p>
Creates a new <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> by scaling <em class="parameter"><code>src</code></em> to <em class="parameter"><code>dest_width</code></em> x
<em class="parameter"><code>dest_height</code></em> and compositing the result with a checkboard of colors
<em class="parameter"><code>color1</code></em> and <em class="parameter"><code>color2</code></em>.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>src</code></em> :</span></p></td>
<td> a <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_width</code></em> :</span></p></td>
<td> the width of destination image
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_height</code></em> :</span></p></td>
<td> the height of destination image
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>interp_type</code></em> :</span></p></td>
<td> the interpolation type for the transformation.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>overall_alpha</code></em> :</span></p></td>
<td> overall alpha for source image (0..255)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>check_size</code></em> :</span></p></td>
<td> the size of checks in the checkboard (must be a power of two)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>color1</code></em> :</span></p></td>
<td> the color of check at upper left
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>color2</code></em> :</span></p></td>
<td> the color of the other check
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> the new <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>, or <a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL--CAPS"
><code class="literal">NULL</code></a> if not enough memory could be
allocated for it.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="gdk-pixbuf-composite"></a><h3>gdk_pixbuf_composite ()</h3>
<pre class="programlisting">void                gdk_pixbuf_composite                (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *dest,
                                                         int dest_x,
                                                         int dest_y,
                                                         int dest_width,
                                                         int dest_height,
                                                         double offset_x,
                                                         double offset_y,
                                                         double scale_x,
                                                         double scale_y,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type,
                                                         int overall_alpha);</pre>
<p>
Creates a transformation of the source image <em class="parameter"><code>src</code></em> by scaling by
<em class="parameter"><code>scale_x</code></em> and <em class="parameter"><code>scale_y</code></em> then translating by <em class="parameter"><code>offset_x</code></em> and <em class="parameter"><code>offset_y</code></em>.
This gives an image in the coordinates of the destination pixbuf.
The rectangle (<em class="parameter"><code>dest_x</code></em>, <em class="parameter"><code>dest_y</code></em>, <em class="parameter"><code>dest_width</code></em>, <em class="parameter"><code>dest_height</code></em>)
is then composited onto the corresponding rectangle of the
original destination image.
</p>
<p>
When the destination rectangle contains parts not in the source 
image, the data at the edges of the source image is replicated
to infinity. 
</p>
<p>
</p>
<div class="figure">
<a name="pixbuf-composite-diagram"></a><p class="title"><b>Figure 1. Compositing of pixbufs</b></p>
<div class="figure-contents"><div><img src="composite.png" alt="Compositing of pixbufs"></div></div>
</div>
<p><br class="figure-break"></p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>src</code></em> :</span></p></td>
<td> a <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest</code></em> :</span></p></td>
<td> the <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> into which to render the results
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_x</code></em> :</span></p></td>
<td> the left coordinate for region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_y</code></em> :</span></p></td>
<td> the top coordinate for region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_width</code></em> :</span></p></td>
<td> the width of the region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_height</code></em> :</span></p></td>
<td> the height of the region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>offset_x</code></em> :</span></p></td>
<td> the offset in the X direction (currently rounded to an integer)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>offset_y</code></em> :</span></p></td>
<td> the offset in the Y direction (currently rounded to an integer)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>scale_x</code></em> :</span></p></td>
<td> the scale factor in the X direction
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>scale_y</code></em> :</span></p></td>
<td> the scale factor in the Y direction
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>interp_type</code></em> :</span></p></td>
<td> the interpolation type for the transformation.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>overall_alpha</code></em> :</span></p></td>
<td> overall alpha for source image (0..255)
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="gdk-pixbuf-composite-color"></a><h3>gdk_pixbuf_composite_color ()</h3>
<pre class="programlisting">void                gdk_pixbuf_composite_color          (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *dest,
                                                         int dest_x,
                                                         int dest_y,
                                                         int dest_width,
                                                         int dest_height,
                                                         double offset_x,
                                                         double offset_y,
                                                         double scale_x,
                                                         double scale_y,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkInterpType" title="enum GdkInterpType">GdkInterpType</a> interp_type,
                                                         int overall_alpha,
                                                         int check_x,
                                                         int check_y,
                                                         int check_size,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint32"
>guint32</a> color1,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint32"
>guint32</a> color2);</pre>
<p>
Creates a transformation of the source image <em class="parameter"><code>src</code></em> by scaling by
<em class="parameter"><code>scale_x</code></em> and <em class="parameter"><code>scale_y</code></em> then translating by <em class="parameter"><code>offset_x</code></em> and <em class="parameter"><code>offset_y</code></em>,
then composites the rectangle (<em class="parameter"><code>dest_x</code></em> ,<em class="parameter"><code>dest_y</code></em>, <em class="parameter"><code>dest_width</code></em>,
<em class="parameter"><code>dest_height</code></em>) of the resulting image with a checkboard of the
colors <em class="parameter"><code>color1</code></em> and <em class="parameter"><code>color2</code></em> and renders it onto the destination
image.
</p>
<p>
See <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-composite-color-simple" title="gdk_pixbuf_composite_color_simple ()"><code class="function">gdk_pixbuf_composite_color_simple()</code></a> for a simpler variant of this
function suitable for many tasks.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>src</code></em> :</span></p></td>
<td> a <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest</code></em> :</span></p></td>
<td> the <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a> into which to render the results
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_x</code></em> :</span></p></td>
<td> the left coordinate for region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_y</code></em> :</span></p></td>
<td> the top coordinate for region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_width</code></em> :</span></p></td>
<td> the width of the region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dest_height</code></em> :</span></p></td>
<td> the height of the region to render
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>offset_x</code></em> :</span></p></td>
<td> the offset in the X direction (currently rounded to an integer)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>offset_y</code></em> :</span></p></td>
<td> the offset in the Y direction (currently rounded to an integer)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>scale_x</code></em> :</span></p></td>
<td> the scale factor in the X direction
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>scale_y</code></em> :</span></p></td>
<td> the scale factor in the Y direction
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>interp_type</code></em> :</span></p></td>
<td> the interpolation type for the transformation.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>overall_alpha</code></em> :</span></p></td>
<td> overall alpha for source image (0..255)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>check_x</code></em> :</span></p></td>
<td> the X offset for the checkboard (origin of checkboard is at -<em class="parameter"><code>check_x</code></em>, -<em class="parameter"><code>check_y</code></em>)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>check_y</code></em> :</span></p></td>
<td> the Y offset for the checkboard 
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>check_size</code></em> :</span></p></td>
<td> the size of checks in the checkboard (must be a power of two)
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>color1</code></em> :</span></p></td>
<td> the color of check at upper left
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>color2</code></em> :</span></p></td>
<td> the color of the other check
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="GdkPixbufRotation"></a><h3>enum GdkPixbufRotation</h3>
<pre class="programlisting">typedef enum {
	GDK_PIXBUF_ROTATE_NONE             =   0,
	GDK_PIXBUF_ROTATE_COUNTERCLOCKWISE =  90,
	GDK_PIXBUF_ROTATE_UPSIDEDOWN       = 180,
	GDK_PIXBUF_ROTATE_CLOCKWISE        = 270
} GdkPixbufRotation;
</pre>
<p>
The possible rotations which can be passed to <a class="link" href="gdk-pixbuf-scaling.html#gdk-pixbuf-rotate-simple" title="gdk_pixbuf_rotate_simple ()"><code class="function">gdk_pixbuf_rotate_simple()</code></a>.
To make them easier to use, their numerical values are the actual degrees.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><a name="GDK-PIXBUF-ROTATE-NONE--CAPS"></a><span class="term"><code class="literal">GDK_PIXBUF_ROTATE_NONE</code></span></p></td>
<td>No rotation.
</td>
</tr>
<tr>
<td><p><a name="GDK-PIXBUF-ROTATE-COUNTERCLOCKWISE--CAPS"></a><span class="term"><code class="literal">GDK_PIXBUF_ROTATE_COUNTERCLOCKWISE</code></span></p></td>
<td>Rotate by 90 degrees.
</td>
</tr>
<tr>
<td><p><a name="GDK-PIXBUF-ROTATE-UPSIDEDOWN--CAPS"></a><span class="term"><code class="literal">GDK_PIXBUF_ROTATE_UPSIDEDOWN</code></span></p></td>
<td>Rotate by 180 degrees.
</td>
</tr>
<tr>
<td><p><a name="GDK-PIXBUF-ROTATE-CLOCKWISE--CAPS"></a><span class="term"><code class="literal">GDK_PIXBUF_ROTATE_CLOCKWISE</code></span></p></td>
<td>Rotate by 270 degrees.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="gdk-pixbuf-rotate-simple"></a><h3>gdk_pixbuf_rotate_simple ()</h3>
<pre class="programlisting"><a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *         gdk_pixbuf_rotate_simple            (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a class="link" href="gdk-pixbuf-scaling.html#GdkPixbufRotation" title="enum GdkPixbufRotation">GdkPixbufRotation</a> angle);</pre>
<p>
Rotates a pixbuf by a multiple of 90 degrees, and returns the
result in a new pixbuf.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>src</code></em> :</span></p></td>
<td> a <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>angle</code></em> :</span></p></td>
<td> the angle to rotate by
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> the new <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>, or <a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL--CAPS"
><code class="literal">NULL</code></a> if not enough memory could be
allocated for it.

</td>
</tr>
</tbody>
</table></div>
<p class="since">Since 2.6</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="gdk-pixbuf-flip"></a><h3>gdk_pixbuf_flip ()</h3>
<pre class="programlisting"><a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *         gdk_pixbuf_flip                     (const <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf">GdkPixbuf</a> *src,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"
>gboolean</a> horizontal);</pre>
<p>
Flips a pixbuf horizontally or vertically and returns the
result in a new pixbuf.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>src</code></em> :</span></p></td>
<td> a <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>horizontal</code></em> :</span></p></td>
<td> <a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE--CAPS"
><code class="literal">TRUE</code></a> to flip horizontally, <a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#FALSE--CAPS"
><code class="literal">FALSE</code></a> to flip vertically
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> the new <a class="link" href="gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"><span class="type">GdkPixbuf</span></a>, or <a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL--CAPS"
><code class="literal">NULL</code></a> if not enough memory could be
allocated for it.

</td>
</tr>
</tbody>
</table></div>
<p class="since">Since 2.6</p>
</div>
</div>
<div class="refsect1" lang="en">
<a name="gdk-pixbuf-scaling.see-also"></a><h2>See Also</h2>
<p>
    <a
href="/usr/share/gtk-doc/html/gdk/gdk-GdkRGB.html"
>GdkRGB</a>.
  </p>
</div>
</div>
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